<?php 
asd();
?>

保存此并将其作为网页打开
错误应该像

[Thu Mar 29 10:28:41 2012] [error] [client 106.132.155.92] PHP Fatal error:  Call to undefined function asd() in * on line 2
[Thu Mar 29 10:28:41 2012] [error] [client 106.132.155.92] PHP Stack trace:
[Thu Mar 29 10:28:41 2012] [error] [client 106.132.155.92] PHP   1. {main}() *:0

尝试使用

error_log("I Love error", 0);

查看更多文档
http://php.net/manual/en/function.error-log.php

ini_set('display_errors',1); 
error_reporting(E_ALL);    
echo =>

它将产生如下错误

Parse error: syntax error, unexpected T_DOUBLE_ARROW in *filename* 
on line *line number*

这对我很有效：

error_log("This is the error message written to the log", 0);